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authorAndreas Gruenbacher <agruenba@redhat.com>2021-06-21 22:28:50 +0200
committerAndreas Gruenbacher <agruenba@redhat.com>2021-06-28 14:13:38 +0200
commitd3c51c55cb9274dd43c156f1f26b5eb4d5f2d58c (patch)
tree8e94b737f7b6c5cc9ba014cfc7fa8cfa3a3ca1e6 /fs/gfs2/file.c
parent38a618dbf47f837f11df01052977dcaf31c5c2a8 (diff)
gfs2: Fix underflow in gfs2_page_mkwrite
On filesystems with a block size smaller than PAGE_SIZE and non-empty files smaller then PAGE_SIZE, gfs2_page_mkwrite could end up allocating excess blocks beyond the end of the file, similar to fallocate. This doesn't make sense; fix it. Reported-by: Bob Peterson <rpeterso@redhat.com> Fixes: 184b4e60853d ("gfs2: Fix end-of-file handling in gfs2_page_mkwrite") Cc: stable@vger.kernel.org # v5.5+ Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Diffstat (limited to 'fs/gfs2/file.c')
-rw-r--r--fs/gfs2/file.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 7b757195fd97..37041873bb95 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -450,8 +450,8 @@ static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf)
file_update_time(vmf->vma->vm_file);
/* page is wholly or partially inside EOF */
- if (offset > size - PAGE_SIZE)
- length = offset_in_page(size);
+ if (size - offset < PAGE_SIZE)
+ length = size - offset;
else
length = PAGE_SIZE;